Showing papers on "Converters published in 1977"
14 Jun 1977
TL;DR: A method for modelling switching converters in the discontinuous conucction mode is developed, whose starting point is the unified state-space representation, and whose end results is a complete linear circuit model which correctly represents all essential features, namly, the input, output, and transfer properties.
Abstract: A method for modelling switching converters in the discontinuous conucction mode is developed, whose starting point is the unified state-space representation, and whose end results is a complete linear circuit model which correctly represents all essential features, namly, the input, output, and transfer properties (static dc as well as dynamic ac small signal). While the method is generally applicable to any switching converter operating in the discontinuous conduction mode, it is extensively illustrated for the three common power stages (buck, boost, and buck-boost). The results for these converters are then easily tabulated owing to the fixed equivalent circuit topology of their canonical circuit model. The outlined method lends itself easily to investigation of the discontinuous conduction mode in more complex structures (cascade connection of buck and boost converters, for example), in which more thean one inductor current may become discontinuous. As opposed to other modelling techniques, the new method considers the discontinuous conduction mode as a special case of the continuous conduction mode.
429 citations
14 Jun 1977
TL;DR: Digital computer simulations of dc-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance.
Abstract: Mathematical representations of a state-plane switching boundary employed in a state-trajectory control law for dc-to-dc converters are derived. Several levels of approximation to the switching boundary equations are presented, together with an evaluation of the effects of nonidea1 operating characteristics of converter power stage components on the shape and location of the boundary and the behavior of a system controlled by it. Digital computer simulations of dc-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance.
50 citations
TL;DR: In this paper, a low frequency, small signal model, valid for all types of converters, both in the heavy and the light mode of conduction, is developed in block diagram form.
Abstract: A low frequency, small signal model, valid for all types of converters, both in the heavy and the light mode of conduction, is developed in block diagram form. The model provides a clear insight into the behavior of such converters and enhances the respective contributions of input and output filters.
41 citations
14 Jun 1977
TL;DR: In this paper, a state-trajectory control law for a family of energy-storage dc-to-dc converters has been implemented for the voltage step-up configuration.
Abstract: A recently proposed state-trajectory control law for a family of energy-storage dc-to-dc converters has been implemented for the voltage step-up configuration. Two methods of realization are discussed; one employs a digital processor and the other uses analog computational circuits. Performance characteristics of experimental voltage step-up converters operating under the control of each of these implementations are reported and compared to theoretical predictions and computer simulations.
22 citations
14 Jun 1977
TL;DR: A linear continuous low frequency small signal model, valid for all types of converters (boost,buck, buck boost), both in heavy and light modes, is presented and a computer program, using state analysis, has been developed allowing the automatic performance analysis of complete controlled converters.
Abstract: A linear continuous low frequency small signal model, valid for all types of converters (boost,buck, buck boost), both in heavy and light modes, is presented in this paper. Its interesting characteristics are that it is valid for free running as well as for fixed frequency converters and that it allows easily to take into account both input and output filters. Thanks to its modularity and its simple general form, it gives a strong insight into the influence of various parameters. (such as input filters) on performance dynamics and into the design of efficient control loops. Finally, a computer program, using state analysis, has been developed allowing the automatic performance analysis of complete controlled converters.
19 citations
TL;DR: In this article, an attempt is made to find and to discover a mathematical method for analysis of the electromagnetic processes in ac-dc and/or dc-ac converters, based on the application of difference equations, makes it possible to describe the behaviour of converters in steady-state and transient processes.
Abstract: In this series of articles, an attempt is made to find and to discover a mathematical method for analysis of the electromagnetic processes in ac-dc and/or dc-ac converters. This method based on the application of difference equations, makes it possible to describe the behaviour of converters in steady-state and transient processes. Analysis is applied to full-wave and half-wave power converters regardless of their specific schemes. The project will include 3 articles in this series: 1) General equations of ac-dc power converters for steady-state and transient processes, 2) Transient processes of ac-dc power converters, 3) Steady-state processes of ac-dc power converters. This series is a result of the author's investigations, begun at the Academy of Sciences of the USSR in 1969 and finished at the Ben-Gurion University of the Negev in 1975. The first stage of investigation was based on [1, 2]. Some first results were published [3, 4].
18 citations
TL;DR: In this paper, two circuits employing operational amplifiers are considered for converting temperature to time, and the theoretical deviation curves obtained show that these time converters have wide range of temperature for given slope and percentage of linearity.
Abstract: In this short paper, two circuits [1], which employ operational amplifiers are considered for converting temperature to time A procedure, suggested in [2] is employed to obtain a wide range of temperature The theoretical deviation curves obtained show that these time converters have wide range of temperature for given slope and percentage of linearity
12 citations
TL;DR: In this article, a new control scheme for parallel multiterminal dc systems is proposed, which is divided into two separate functions: (1) a supervisory control called the System Monitor-State Predictor (SMSP), which determines the steady state operating point of the system from ac voltage measurements, power requirements at the converters, and the dc network configuration; and (2) the feedback controllers which drive the system to the desired operating point supplied by the SMSP.
Abstract: A new control scheme for parallel multiterminal dc systems is proposed. The scheme is divided into two separate functions: (1) a supervisory control called the System Monitor-State Predictor (SMSP), which determines the steady state operating point of the system from ac voltage measurements, power requirements at the converters, and the dc network configuration; and (2) the feedback controllers which drive the system to the desired operating point supplied by the SMSP. A systematic method is presented for calculating local feedback gains based on optimal control theory, and it is shown that use of feedback measurements is possible with negligible loss of dynamic performance. A detailed hybrid computer simulation of a four-terminal dc system was used to demonstrate the excellent performance of the new control scheme during steady state operation and for large system disturbances.
12 citations
TL;DR: In this article, a generalized computer-aided modeling and analysis of DC-DC converters is presented, which is applicable to all types of power stages and duty-cycle control, including continuous and discontinuous inductor current operation.
5 citations
TL;DR: This model has been investigated in order to facilitate digital simulation of the static converters and a method for computing the connection matrix is described for one of these converters.
Abstract: A mathematical model using connection matrices is proposed for static converters. This model has been investigated in order to facilitate digital simulation of the static converters. Validity conditions of this model are first established and then illustrated by some examples. A method for computing the connection matrix is described for one of these converters.
25 Apr 1977
TL;DR: An analytically derived approach to the control of energy storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented in this article.
Abstract: An analytically derived approach to the control of energy-storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented. The control approach is derived from a state-plane analysis of dc-to-dc converter power stages which enables a graphical visualization of the movement of the system state during both steady state and transient operation. This graphical representation of the behavior of dc-to-dc converter systems yields considerable qualitative insight into the cause and effect relationships which exist between various commonly used converter control functions and the system performance which results from them.
Proceedings Article•
01 Sep 1977TL;DR: In this article, the transfer characteristics of ADCs under dynamic operating conditions were determined by using digital techniques and specifications such as signal-to-noise ratio and differential nonlinearity were derived.
Abstract: Digital techniques are proposed to determine the transfer characteristics of ADCs under dynamic operating conditions. Specifications such as signal-to-noise ratio and differential nonlinearity are derived. Measurements show the discrepancy between static and dynamic performance.
Patent•
22 Jan 1977
TL;DR: In this paper, a starting method of DC high voltage power transmission system unnecessary to take synchronism of starting operation to forward and reverse converters by using a gate pulse having a narrow width, of less consumed control power.
Abstract: PURPOSE:A starting method of DC high voltage power transmission system unnecessary to take synchronism of starting operation to forward and reverse converters by using a gate pulse having a narrow width, of less consumed control power
Patent•
14 Feb 1977
TL;DR: In this article, an apparatus capable of detecting failures concerning converters in a converter station comprising transformers T for converters, converters V1... V6, power distribution lines and the likes while distinguishing them form the failures in other equipments is presented.
Abstract: PURPOSE:An apparatus capable of detecting failures concerning converters in a converter station comprising transformers T for converters, converters V1 ... V6, power distribution lines and the likes while distinguishing them form the failures in other equipments.
25 Apr 1977
TL;DR: An analytically derived approach to the control of energy storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented in this paper.
Abstract: An analytically derived approach to the control of energy-storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented. The control approach is derived from a state-plane analysis of dc-to-dc converter power stages which enables a graphical visualization of the movement of the system state during both steady state and transient operation. This graphical representation of the behavior of dc-to-dc converter systems yields considerable qualitative insight into the cause and effect relationships which exist between various commonly used converter control functions and the system performance which results from them.
TL;DR: In this paper, a new circuit is described which enables the compensation of rapid changes in the reactive loading of a supply system or of disturbances on the system, which can accept leading currents from the supply, allowing a reduction in size of the capacitor banks normally required.
TL;DR: In this article, a simple common turn-off facility is used for single-phase and three-phase a.c. rectification with small reactive power by means of converters connected to single phase and three phase systems requires forced commutation.
01 Oct 1977
TL;DR: In this paper, the effect of the variable capacitance of the diode's elements on the frequency converters was investigated, and the transmission, impedance, and noise characteristics of the frequency converter were examined.
Abstract: Millimeter-wave frequency converters on a diode with a Schottky barrier were analyzed The analysis includes investigation of the effect of the variable capacitance of the diode's elements on the frequency converters Specifically, the transmission, impedance, and noise characteristics of the frequency converters were examined
Patent•
04 Aug 1977
TL;DR: In this article, the authors propose a remote supply for parallel telecommunications repeater amplifiers, which transmits dc currents to dc/dc converters connected in parallel between the two wires, and the output of each converter supplies a repeater amplifier.
Abstract: The remote supply, for parallel telecommunications repeater amplifiers, transmits dc currents to dc/dc converters connected in parallel between the two wires. The output of each converter supplies a repeater amplifier. The converters draw a constant current. Each converter consists of an input dc-to-pulse inverter coupled via a tapped transformer to a rectifier and smoothing circuit. A constant current regulator may be connected before each converter and/or a constant voltage regulator after it. The converter's transfer ratio is set in-situ.
TL;DR: The No. 4 ess system is powered from a 140-volt battery plant as mentioned in this paper, where modular dc-to-dc converters located in system frames are used to change the 140 volts to the many well regulated voltages needed by the ess circuitry.
Abstract: The No. 4 ess system is powered from a 140-volt battery plant. Modular dc-to-dc converters located in system frames are used to change the 140 volts to the many well regulated voltages needed by the ess circuitry. The 24- and 48-volt power required by the system is provided by bulk dc-to-dc converters with 140 volts as an input. The modular converters require no field adjustments, are pluggable, and contain many alarm and shutdown features, some of which are routinely tested by the system. The 24- and 48-volt bulk converters are available in 2.5- and 5-kilowatt sizes and, similar to the modular converters, contain many alarm and shutdown features for the protection of their 24- and 48-volt buses. All converters are designed for low emi (electromagnetic interference) emission and to operate in a room ambient of 0 to 50°C with in frame ambients as high as 75°C. As a function of the output voltage, efficiencies range from 65 to 85 percent. Most converters regulate remotely with typical end-of-life regulation performance of better than ±2.5 percent.
01 Jan 1977
TL;DR: In this paper, the effect of source impedance of various types (R, L, or C) on the output voltage, and the minimum value of inductance required on the DC side to provide continuous load current for both active and passive loads are discussed.
Abstract: The method by which AC supply voltage is used for the commutation of conducting SCRs has been discussed in Chapter 6; it is very convenient for both rectification and inversion in phase-controlled bridge circuits and midpoint-connection circuits. This method of commutation is referred to as class F type of commutation (see Chapter 8), and is also known as line commutation. All types of AC to variable voltage DC converters used for motor control and regulated power supplies, in both of which the AC input current is made continuous by a large reactor on the DC side, make use of line commutation without any external commutating components. The input-output characteristics of such line-commutated converters will be considered in detail in this chapter. The effect of source impedance of various types (R, L, or C) on the output voltage, and the minimum value of inductance required on the DC side to provide continuous load current for both active and passive loads will also be discussed.
01 Aug 1977
TL;DR: In this paper, the authors deal with radiated susceptibility standards and design techniques for control and reducing susceptibility in open frame DC-DC converters, where critical components and wiring are identified and methods of reducing susceptibility are discussed.
Abstract: This paper deals with radiated susceptibility standards and design techniques for control ling and reducing susceptibility in open frame DC-DC converters.. The standards selected pro vide protection for most converters without causing undue cost penalty to the many con verters that never encounter high EM fields. Critical components and wiring are identified and methods of reducing susceptibility are discussed. Two test setups are discussed that produce a highly accurate EM field and results are shown that demonstrate the increase in susceptibility level achieved.